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Doug WaltonFlag for United States of America

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Anyone have rain barrel pump suggestions?

I quickly setup some rain "barrels" during the last storm a few weeks ago so I would have some water for my garden before summer got here and the rain stopped.  I didn't have time to build a raised platform for them so they're just sitting on the ground and the water pressure is pretty low.  They are slightly uphill from my garden so it still works, just not great.

I'm looking for an electric or solar pump I can hookup to the spout at the bottom of the rain barrel and connect a garden hose on the other end to make watering faster.  Is anyone familiar with some pumps like this?  I spent a while searching on amazon and google without much luck, but maybe I'm using the wrong terms.

Ideally something temporary/cheaper is fine, my long term plan is to build a raised platform 3-4 feet higher for them, but I have 275 gallons of water to use first now.

I have an adapter on the spout for a garden hose, so a pump that can take a garden house input and output would probably be the best.

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Dr. Klahn

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Awesome, this is great advice, thank you!  

I didn't realize most of the resistance was coming from the garden hose, but that makes sense and is most likely the main problem (doesn't help that it's a 50 foot hose when I only need about 15 feet).  I'll try out some different piping before looking into a pump.

Thanks again!
Hi Doug

I know the question has been answered with an excellent explanation, but I thought I would post a comment because I had been thinking about this problem on and off since I saw the question yesterday.

Here in the UK we commonly fit wall mounted electric showers either over the bath or in cubicles.  During my vacation in America last year I realised that these are not common, and you may not be familiar with them.  They are small wall-mounted units with an integrated heating element and rotary thermostat that simply heats incoming mains water as it passes through to the shower head, and they therefore require a certain amount of water pressure to work.  Some work OK from attic cold water storage tanks, but only older houses now have these.  They are rated from about 7kW up to 10.5kW.  The lower powered ones have trouble discharging enough water through the shower rose during Winter when the incoming water is cold and the thermostat has to be turned up higher, but 9kW and upwards are more efficient in this respect.

These units have been around for decades.  The previous method used for showers was to employ a standard mixer tap that combined incoming mains cold water with hot water from an insulated hot water storage tank often mounted in an attic, however few houses in the UK still have hot water storage tanks since the move to gas "combi-boilers" that supply instant hot water.  Those who use mixer tap showers that combine the instantaneous heated water with cold mains water usually have to add an in-line pump to increase the pressure.

Some electric showers have an in-built electric pump that makes them "power showers", whereas others can make their standard electric showers into "power showers" by adding an in-line pump on the incoming cold mains pipe.

Those pumps were the first thought I had about your own issue, but when I looked at these in-line water pumps I quickly realised that they would not increase the water pressure from your storage tanks enough to water the garden much more (if at all) efficiently through a standard hose pipe.  You have to remember that a domestic shower has hundreds of very small holes in the shower rose whereas even a garden sprinkler end for your hose has larger holes and is at the end of a much longer pipe that is probably of greater inside diameter than that of the flexi-hose of a shower.

One thing that might be inhibiting the water flow from your tanks, apart from elevation, is if you haven't removed the screw-on caps.  From memory these multi-purpose tanks have a small hole that acts as an expansion vent and to allow air in when the liquid is being drained off through the tap at the bottom.  If the hole isn't large enough it could be causing a vacuum.  Conversely, if you were able to actually pressurise the head of air in the tank to force the water through the hose it would help, but I haven't been able to think of anything that might allow you to do this.

Just my thoughts.
Thanks BillDL!  I'll have to check out those inline pumps.  I have to double check, but I think I have the cap loosely on to keep mosquitoes from laying eggs in there.  I'll try removing it completely when I water and also look for those air holes and make sure it's open.

I'm currently planning on getting some black pvc or drip-line type hose (Dr. Klahn's B and C recommendations) and running it to each planter.  Gravity is probably enough for now, but when I get down to a water level in the tank that is lower than the planters I'm going to need something to push it over the edge and it shouldn't  need to be very strong for that.  

Conversely, if you were able to actually pressurise the head of air in the tank to force the water through the hose it would help, but I haven't been able to think of anything that might allow you to do this.

This is a cool idea, and I do have a 20 gallon air compressor.  It might be fun to try and rig something together to see if that could work.  As long as it's air-tight, the tanks seem pretty strong and might be able to take some pressure.
The cage around the thick plastic tank would stop it from ballooning out, but the weak point might be at the screw-in tap.  I suppose all you would be doing is supplying enough pressure to push water through the hose with more force, so it's not as though you would be pumping up the tank almost to bursting point.  Of course, water doesn't compress so you would only be compressing the head of air.  As the water level goes down it would be harder to pressurise the larger volume of air.  You get this symptom with hand-held or back pack weed killer pumps.  As the liquid goes down you have to keep pumping it up more frequently until it becomes a pain in the butt.

The water pumps for domestic showers are ridiculously expensive.  It's probably because they have been engineered to run as quietly as possible.  I personally wouldn't buy one for the sole purpose of using it to water the garden, but maybe you can get one 2nd-hand.  I don't know much about water wells in rural houses beyond city water reaches other than the fact that they are incredibly expensive to bore out.  A friend of mine in the raisin producing area of California had to have a new one drilled and it cost something like $16,000 to $20,000.  As far as I understand the pumps are submersible and are fixed just below the water level in the well.  They must be pretty powerful to pull water up about 200 feet from near the bottom of the well and then push it up about the same distance again to a storage tank that is elevated above ground.  I would imagine that the pump draws up the water through a fairly large bore pipe compared with the smaller bore that feeds the house.  I'm not sure if the storage tanks are pressurised or if they use a pump that kicks in when water is drawn off in the house.

Maybe you could look into salvaging and repairing/refurbishing an old well pump.  I would guess that the two main failure issues are mud being sucked into them as wells run dry and motor burn-out.  If you could get your hands on a pump that has a working motor but is clogged up you might have a feasible project, but I would guess that well drilers and pump suppliers probably refurbish their own and you might not get one for free or for a token amount.
I don't think you would get a lot of water pressure from those electrically powered emergency pumps for dealing with flooded basements or for draining ponds, but 2 stroke gas powered ones would probably be more efficient.  They seem to be rated in Horse Power and I haven't had a look at the specifications for the ones that come up in a search at Home Depot:

https://www.homedepot.com/b/Plumbing-Pumps/N-5yc1vZbqlb

https://www.homedepot.com/b/Plumbing-Pumps-Utility-Pumps/N-5yc1vZbqn6

Maybe you could pick up something 2nd-hand.

Get a 5 gallon container and ascertain how long it takes to fill it by gravity from the tank and that will give you a measurement to use in comparing pumps.  You can always pour it back into your tank again.